1. Field of the Invention
The present invention relates to a fermented bagasse feed and its preparation and uses, more particularly to a fermented bagasse feed prepared from an alkali-treated bagasse and its preparation as well as uses.
2. Description of the Prior Art
Bagasse, a squeezed waste of sugar cane, contains a vast amount of of cellulose and hemicellulose. Although having been used in part as fuel sources, it is a typical unutilized agricultural waste which could not find other useful applications. The problem is that more than 100 million tons of bagasse produced annually worldwide have been still unutilized.
On the other hand, livestock bred with grass, or ruminants like cattle and sheep, naturally assimilate cellulose and hemicellulose of plants, unlike monogastric animals like human beings, pigs and poultry, and utilize physiologically said cellulose and hemicellulose as energy sources.
Recently, the consumption of livestock products like beef and dairy products has increased and intensive livestock farming system has been remarkably developed so that a lot of cattle standing in the same direction have been bred together in a small shed, and said intensive livestock farming system has tightened the supply of feed grass sufficient for breeding and also led to the rapid increase of the demand for roughage containing cellulose and hemicellulose substitutable for feed grass.
Researches to utilize bagasse as roughage have proceeded for a long time, however, because in addition to cellulose and hemicellulose, bagasse contains a considerable amount of lignin having a tight linkage with fibre like cellulose and also said linkage tightens the structure of bagasse as in bamboo. In case that ruminants could assimilate bagasse itself, the digestibility of bagasse for ruminants is relatively low and the taste and value of bagasse for ruminants is very unpreferable. It is known that when bagasse is assimilated by cattle, there is a danger that pieces of said bagasse could be stuck into the walls of the cattle's rumen.
For improving nutrient value of bagasse, there were many proposals for increasing the digestibility of bagasse by decomposing lignin to soften the structure of bagasse. Many of these proposals comprise treating bagasse with alkali and then fermenting the alkali-treated bagasse. In such alkali treatment, as described in Biotechnology and Bioengineering, volume 26, pp. 426-433 (1984), using alkaline reagents such as sodium hydroxide, calcium hydroxide and sodium carbonate is known. In the fermentation of an alkali-treated bagasse, for instance, as described in Animal Feed Science and Technology, volume 9, pp. 1-17 (1983), ensilage of an alkali-treated bagasse using sodium hydroxide is known.
We eagerly studied these conventional methods and found that in the case of using sodium hydroxide in an alkali treatment, the pH level of alkali-treated bagasse was decreased very gradually over a long period of time to the range wherein lactic acid bacteria were capable of proliferating, and that further a long period of 25 to 90 days was required for preparing a fermented bagasse feed from said alkali-treated bagasse, and it was found that, in order to avoid said disadvantage and to increase rapidly the pH level of alkali-treated bagasse, said alkali-treated bagasse should be neutralized with an acid solution. Furthermore, it was found that in the case of using sodium hydroxide, a relatively small amount of sodium hydroxide kept the pH of the bagasse mixtures to a relatively-high level because of its strong alkalinity so that lignin could be readily decomposed to soften the structure of bagasse while cellulose and hemicellulose necessary for roughage were also readily decomposed, and that there were many other drawbacks in conventional methods.
It was found that in the case of using calcium hydroxide and sodium carbonate, because of their relatively weak alkalinity, the amounts of alkaline reagents used was increased to the level of about 12 to 30 w/w % to bagasse, on a dry solid basis (the wording of "w/w %" as referred to the invention will be abbreviated as "%" hereinafter) which raised the cost of alkali treatment, while ruminants consumed excessively alkaline reagents and desired a large amount of water so that they should excrete a large amount of urine. Therefore it was found that the above alkali treatment has an extreme drawback to affect physiologically ruminants.